scholarly journals Herbivore Larval Development at Low Springtime Temperatures: The Importance of Short Periods of Heating in the Field

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Esther Müller ◽  
Elisabeth Obermaier

Temperature has been shown to play an important role in the life cycles of insects. Early season feeders in Palaearctic regions profit by the high nutritional quality of their host plants early in the year, but face the problem of having to develop at low average springtime temperatures. This study examines the influence of short periods of heating in the field on larval development and on mortality with the model systemGaleruca tanacetiL. (Coleoptera: Chrysomelidae), an early season feeder, that hatches at low springtime temperatures. Field and laboratory experiments under different constant and variable temperature regimes were performed. While in the field, the average daily temperature was close to the lower developmental threshold of the species of 10.9°C; maximum temperatures of above 30°C were sometimes reached. Larvae developed significantly faster, and pupae were heavier, in the field and in an assay with short periods of heating than at the same average temperature under constant conditions in the laboratory. We conclude that larvae profit substantially from short periods of heating and temperature variation in the field and that intervals of high temperature enable insect survival and exploitation of nutrient-rich food resources at early times in the season.

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509a-509
Author(s):  
C.E. Wieland ◽  
J.E. Barrett ◽  
D.G. Clark ◽  
G. J. Wilfret

Four poinsettia cultivars were grown in glass greenhouses in Gainesville, Fla., in the Fall 1997 to evaluate differences in floral initiation and subsequent development. Three means of regulating photoperiod were 1) natural days 2) long-day lighting to 6 Oct. and then natural days (lights out) 3) long-day lighting to 6 Oct., and then short-day conditions by black cloth for 15 h (black cloth). At 2-day intervals, sample meristems were collected and examined for initiation of reproductive development. Average minimum and maximum temperatures during the first two weeks of October were 22 and 29 °C, respectively, with an average temperature of 25.3 °C. The overall average temperature was 23.2 °C from planting to anthesis. Differences in anthesis dates among cultivars were primarily due to time to initiation vs. rate of development. Under natural days, `Lilo' initiated first on 8 Oct. and `Freedom', `Peterstar', and `Success', followed by 6, 8, and 18 days, respectively. Lights out resulted in `Lilo' initiating 17 Oct., followed by `Freedom', `Peterstar', and `Success' initiating 7, 12, and 15 days later, respectively. Differences between cultivars in time of initiation was reduced under black cloth, where `Lilo' initiated 14 Oct., followed by `Freedom' 2 days later, and `Peterstar' and `Success' 7 days afterward. Initiation was positively correlated to visible bud and anthesis. First color was positively correlated to initiation and visible bud, with the exception of `Lilo'. Growth room studies conducted using various high temperatures and photoperiods indicated similar trends.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2217
Author(s):  
Daniela Șova ◽  
Mariana Domnica Stanciu ◽  
Sergiu Valeriu Georgescu

Investigating the large number of various materials now available, some materials scientists promoted a method of combining existing materials with geometric features. By studying natural materials, the performance of simple constituent materials is improved by manipulating their internal geometry; as such, any base material can be used by performing millimeter-scale air channels. The porous structure obtained utilizes the low thermal conductivity of the gas in the pores. At the same time, heat radiation and gas convection is hindered by the solid structure. The solution that was proposed in this research for obtaining a material with porous structure consisted in perforating extruded polystyrene (XPS) panels, as base material. Perforation was performed horizontally and at an angle of 45 degrees related to the face panel. The method is simple and cost-effective. Perforated and simple XPS panels were subjected to three different temperature regimes in order to measure the thermal conductivity. There was an increase in thermal conductivity with the increase in average temperature in all studied cases. The presence of air channels reduced the thermal conductivity of the perforated panels. The reduction was more significant at the panels with inclined channels. The differences between the thermal conductivity of simple XPS and perforated XPS panels are small, but the latter can be improved by increasing the number of channels and the air channels’ diameter. Additionally, the higher the thermal conductivity of the base material, the more significant is the presence of the channels, reducing the effective thermal conductivity. A base material with low emissivity may also reduce the thermal conductivity.


2021 ◽  
Vol 13 (1) ◽  
pp. 427
Author(s):  
Magdalena Rykała ◽  
Łukasz Rykała

The article describes the issues of transport of bulk materials. The knowledge of this process has a key impact on the rational planning of transport tasks. It is necessary to have knowledge about the transport services market and the competition that exists in it. In order to achieve a competitive advantage on the market, enterprises should analyze data on the implementation of transport tasks on an ongoing basis. It is also important that the costs incurred from the conducted activity are minimized, while increasing the quality of services and taking into account the sustainable development of the enterprise. The study analyzes data from a few selected motor vehicles in the period of 3 years of operation, coming from an enterprise specializing in the transport of bulk materials. Moreover, a global sensitivity analysis was performed based on a neural model describing the impact of the analyzed factors on the company’s profit. The results show that the most important factors influencing the company’s profit are the fuel consumption of individual vehicles, the driver (driving style) and the month (average temperature, weather conditions).


2020 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Soomro Dr. Raheem Bux ◽  
Brohi Noor Ahmed ◽  
Memon Khair Muhammad ◽  
Gilal Rehman Gul

The culinary business is being increased rapidly in Pakistan. Usually, Pakistani consumers prefer to eat meals at homes cooked by female members owing to cultural, social and religious reason. In order to bridge up the gap in existing hospitality literature, the objective of this research manuscript is to find out the relation among dimensions of quality (food quality, service quality and quality of physical environment), customer satisfaction, restaurant image, behavioral intentions and customer perceived value in casual restaurants in Sukkur city. Data for this research study have been collected from customers of restaurants located in Sukkur city through convenience sampling. SPSS (24) and Smart PLS (3.0) versions were used for data analysis. Service quality dimensions of causal restaurant were found important determinants of the restaurant image and customer perceived value followed by physical environment and service quality; whereas, the physical environment quality was not found to be a significant factor of perceived value of customer. Additionally, food quality is measured as an important restaurant’s product. Another outcome of the present study exhibited that quality of physical environment holds a substantial positive effect on restaurant image. The findings indicate quality in food and service is highly important to satisfy customers and make their behavior positive about casual restaurant. Further, as an average temperature remains above 400 in Sukkur city, internal environment of the restaurant is significant as it will affect the mood and perception of customers when they dine in the casual restaurant.


Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 832-840 ◽  
Author(s):  
O. Erincik ◽  
L. V. Madden ◽  
D. C. Ferree ◽  
M. A. Ellis

In 1998 and 1999, controlled-environment studies were conducted in growth chambers to determine the temperature and wetness-duration parameters required for leaf and cane infection of grape by Phomopsis viticola. Greenhouse-grown ‘Catawba’ (Vitis labrusca) and ‘Seyval’ (French hybrid) grapes were inoculated with P. viticola and incubated at constant temperatures of 5, 10, 15, 20, 25, 30, and 35°C and at wetness durations of 5, 10, 15, and 20 h for each temperature. Data from each cultivar were analyzed by nonlinear regression analysis to determine the relationship between disease severity and temperature and wetness duration. A generalized form of the Analytis Beta model was found to provide the best fit to the data. Disease severity on leaves and canes increased with increasing wetness duration at most temperatures. Minimum and maximum temperatures for infection were around 5 and 35.5°C, respectively. Optimum temperatures for leaf and cane infection were between 16 and 20°C. In the 2000 and 2001 growing seasons, the generalized Beta model was validated in ‘Catawba’ and ‘Seyval’ vineyards by inoculating vines during natural rain events. Average temperature and hours of wetness for each event and inoculation were recorded and used in the model equation to predict disease severity on leaves and internodes. Correlation coefficients between observed disease severities following field inoculations and predicted disease severities for both cultivars were between 0.71 and 0.81 and always significant (P < 0.01). These results indicate that the model reliably predicted leaf and cane infection on both cultivars over a wide range of wetness durations and temperatures. The model may be useful in developing disease-forecasting systems for Phomopsis cane and leaf spot on grapes.


1972 ◽  
Vol 23 (5) ◽  
pp. 913 ◽  
Author(s):  
AC Kondos ◽  
GL McClymont

The effect on the protein quality of meat meals of processing them under commercial conditions in a continuous dry renderer at maximum temperatures ranging from 116 to 160°C for a running time of 115 min was studied. Although the total levels of amino acids were little affected by processing temperatures, the biological availability of all essential amino acids, as determined by the protozoan Tetrahymena pyriformis, was reduced as the processing temperature increased. At 140 and 160°C the availability of certain amino acids was reduced by 37-56%, lysine, histidine, and methionine being the most severely affected. The availability of essential amino acids in meals produced at temperatures from 121 to c. 138° was not significantly different. The growth-promoting ability of the meat meals for chickens was closely related to the availability of the essential amino acids. __________________ *Part VI, Aust. J. Agric. Res., 19: 171 (1968).


1966 ◽  
Vol 46 (2) ◽  
pp. 195-203 ◽  
Author(s):  
B. Stanfield ◽  
D. P. Ormrod ◽  
H. F. Fletcher

Effects of day/night temperature regimes from 7/4 to 32/24 °C on growth and development of Pisum sativum L. var. Dark Skin Perfection were studied in controlled-environment cabinets. Light intensity was about 1500 foot-candles and the photoperiod was 16 hours. Rate of plant development, in terms of nodes produced per day, increased steadily as the average temperature increased. Rate of stem elongation, however, was most rapid at 21/13 °C; and plant height was greatest at 16/10 °C. On a dry matter accumulation rate basis, vine growth decreased above and below a temperature optimum which shifted from 21/16 to 16/10 °C in the course of plant development. The combination of high day and high night temperatures caused an increase in the number of nodes to the first flower. Tillering was most prolific at the lower temperatures and was absent at 32 °C day temperatures. Pea yield decreased as temperature increased above 16/10 °C, due mainly to a reduction in the number of pods per plant.


2013 ◽  
Vol 773 ◽  
pp. 101-107
Author(s):  
Chun Lei Yang ◽  
Xiao Yan Yuan ◽  
Jun Yu ◽  
Jin Peng Yang ◽  
Shu Yang ◽  
...  

In Hubei Province in China, About 15%-40% yield of Burley tobacco losses caused by mildew during air-curing period for High humidity and low temperature. In this paper, active solar utility system was first applied to condition temperature and humidity in the air-curing process. Forced convection solar collectors, natural convection solar collectors and air circulates system were applied in the solar Burley barns. The results showed that: The cost of the system was about 1226 ¥ per drying barn, but it could quickly increase the temperature and reduce the relative humidity of the barn, and the quality and yield were raised. The collector efficiency was about 18.8-24.9%. The average temperature of barn could be improved to 3-4 °Ceven in rainy days. The quality of upper and middle tobacco was enhanced by 11% to 13%; Yields increased by 18% to 23%; The income per acre added 371-392¥; the average income of tobacco increased from 10.49 to 10.87 ¥ per kilograms .


2008 ◽  
Vol 53 (No. 4) ◽  
pp. 121-125 ◽  
Author(s):  
J. Vegricht ◽  
A. Machálek ◽  
P. Ambrož ◽  
U. Brehme ◽  
S. Rose

The aim of the performed work was to verify the hypothesis that different milking equipments have different influence on the blood circulation in the milk gland during milking. This influence was investigated by measuring the surface temperature of the milk gland using thermography. The influence was monitored of 5 different milking units in total, out of them 2 AMS, on the teat temperature which was scanned and evaluated in the teat tip centre and on the teat base at the same time with the surface temperature of the udder, always at the instant closely preceding the cluster application and then after its removal. It was ascertained that the average temperature of the teat tip after milking was increased in comparison with the temperature before milking practically in all the milking units monitored. At the same time, the average temperature of the teat tip in the milking equipment in parlours increased by about 1.7°C–2.7°C (6.1%–9.0%) as compared to the temperature before milking. At milking in AMS, the temperature rise of the teat tip was smaller and reached only 0.9°C–1.7°C (2.9%–6.0%). At the same time, the temperature of other parts of the milk gland grew commensurately. It was also found that differences exist between different milking units with respect to their influence on the temperature fluctuation of the milk gland. From the monitoring performed up to now and from the results acquired it is possible to apprehend that the monitoring of the teat temperature before and after milking with the help of thermography can become an indicator of the working quality of the milking equipment and its influence on the milk gland. The confirmation of this hypothesis requires, however, further detailed and extensive measuring to be carried out.


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